Tesla has been a huge success under Elon Musk's leadership, rising in value from less than $4 billion six years ago to $59 billion today. On Tuesday, Tesla's board announced that it had convinced Musk to stay at the helm for another decade with a truly gargantuan performance-based pay package.

The pay package is tied to the value of the company's stock as well as revenue and earnings targets. If Tesla's stock never rises above $100 billion, Musk will get nothing for a decade's work as Tesla's CEO (aside from increases in the value of the stock he already has). If the stock reaches a value of $100 billion—and the company either achieves revenues of $20 billion or earnings of $1.5 billion—Musk will get 1 percent of the company's stock, an award worth $1 billion.

Things get a lot more generous from there. If the stock rises to $150 billion (and Musk reaches another revenue or profit target), Musk gets another 1 percent of the stock, which will be worth $1.5 billion. That pattern continues in $50 billion increments until Tesla's stock rises above $650 billion—at which point Musk will get a stock award worth $6.5 billion. Musk's stock awards will total $45 billion if he hits all 12 milestones.

Musk already owns more than 20 percent of Tesla stock. So if Tesla's stock price did rise to $650 billion and Musk got another 12 percent, his net worth would be well in excess of $200 billion—likely making him the wealthiest person in the solar system.

The new deal is also significantly more generous than Musk's previous Tesla compensation plan, which was approved in 2012. At that time, Tesla's stock was worth $3.2 billion. Under the plan, Musk was awarded 0.5 percent of Tesla's outstanding shares each time the company's stock price rose by $4 billion, for a maximum grant of 5 percent of Tesla's shares. This time, not only are the shares worth a lot more, but Musk is getting more of them—1 percent of outstanding shares per milestone rather than 0.5 percent under the old plan.

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Needless to say, there's no guarantee that Musk will hit all of these milestones—or any of them. Tesla has been struggling to ramp up production on the Model 3, its mass-market electric car. And conventional car companies are pouring billions into developing electric cars of their own.

But the targets in Musk's previous pay package seemed pretty ambitious, too—Tesla's value has grown more than 15-fold since then. And if Tesla managed to do for cars what Apple did for smartphones, its value could rise a lot—though $650 billion is a huge number.

Musk's ultimate goal is to fund human exploration of Mars. His other company, SpaceX, has been hard at work on the technology required to send dozens—and eventually hundreds and thousands—of people to the Red Planet. But one of the big questions is how he plans to pay for the venture. Becoming the world's richest man could be a big help.